Unfortunately Google is less and less a cool place for senior software engineers
Pros
more freedom, relevantly less bureaucracy and harassment compare to similar size company. open access to code base, design documents cross all projects. energetic and talented engineers. free meal are very convenient. flexible working hours. core search and ads system have solid code base. solid infrastructures like mapreduce, bigtable, GFS, RPC etc are interesting to build application on. LSE are still positive models for the whole company. distributed offices offer working opportunities for people around the word. MTV main campus is dynamic and vibrate. company still attracts fresh high quality new graduates from top universities. politics is not a huge problem yet.
Cons
Company is getting more bureaucratic. While many engineers are super solid, some managers are only good at suck-up or manage-up, they indulge at meetings to show their influence but unable to really be a model and lead by examples. Some senior engineers are leaving as the freedom to work on innovative project is diminishing. more and more new graduate or junior engineers are hired. While politics are still relative small compare to similar size company, they are certainly growing. managers "promote" lots of tech lead to manage projects regardless whether they are really technically strong. peer-review process is partially broken as manager's feedback is the one that really matters. project transfer process is heavy and become very dis-encouraging.